In general, said kind of powered respirator with an electric fan is comprising of a face piece part that covers at least nose and mouth of a user, an electric fan, a motor which drives the electric fan and a filter and has a structural feature characterizing that clean air from which fine particles drifting in atmosphere are removed by means of the electric fan and the filter to a face of the user. For the above purpose, an air line hose to supply clean air or an electric source cable to transmit electricity to the motor are equipped to the conventional powered respirator, therefore a user who wear the conventional powered respirator feels inconveniences while at work. In particular, in a case of tunnel construction field, a powered respirator equipped with an electric source cable can not be used in a working face where an explosive such as dynamite is used from the safety view point, therefore, a powered respirator without an electric source cable is needed in a working face.
To improve above mentioned problem, various kinds of respirator are proposed, for example, in Patent Document 1, a respirator with an electric fan unit to which a filter and an electric fan are equipped is disclosed. However, this respirator is necessary to provide electric source cables to transmit electricity to electric fan units locating right and left positions from a battery. Further, in Patent Document 2, a powered respirator characterizing, containing a fan unit installing an electric fan in a main body of casing, a filter is equipped to the main body of casing at up stream side to a suction opening of the fan unit, exiting a cylindrical duct between the suction opening of the fan unit and the filter in the main body of casing, and press adhering one end of duct with the suction opening of the fan unit and another end of duct with the filter is disclosed.
Patent Document 1: JP Laid open publication 2003-117013
Patent Document 2: JP Laid open publication 2004-16466